"Not stone or wood," Ianto said, as if making notes on Jack's preferences in some sort of mental notepad. And maybe he was. One never could tell with him. He flushed slightly at Jack's expression and the obvious way the older man was looking at him, looking down and smiling shyly. Even after so long, he still had the ability to get embarrassed by Jack's interest in him. In some ways, the physical attraction still confused him. He understood his own attraction, Jack was gorgeous and anyone had to be mental not to want him, but Jack finding him attractive was somewhat baffling.
"Yes, well, it will clean up easily enough," Ianto said with a shrug, because dirt on his trousers really wasn't what he was focused on right now. "And anyway, I'm sure you can think of some way to make it up to me. You're clever like that." He coloured again at Jack's smile, but returned it with a small smirk of his own. "Of course, sir. What can I do to be of assistance?"